**2. The PRIME-MD Study in Japan**

#### **2.1 Objective**

To define the prevalence and comorbidity of anxiety disorders and depressive disorders in primary care patients in Japan.

#### **2.2 Materials and Methods**

The PRIME-MD [5] was the first instrument designed for use in primary care as diagnostic criteria based on the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM–III-R) [8], and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM–IV) [9]. It is used in clinical settings and has been widely used in clinical research [10–12].

PRIME-MD is a two-step instrument consisting of a self-administered patient questionnaire and a structured clinical interview administered by the physician. The first step is a brief screening instrument in which the patient is required to complete answers in full. A structured interview is subsequently conducted if the result of the patient's screening suggests the presence of a psychiatric diagnosis, which allows for a DSM-IV diagnosis to be assigned if appropriate.

PRIME-MD was used to determine the presence of DSM-IV in the present study, which was conducted from 1998 to 1999. The sample group included 601 adult patients (249 males, 352 females, mean age = 58.9 years, SD = 16.5), who were selected randomly from seven primary care settings and assessed by twelve primary care physicians. Study protocol was approved by the Ethics Committee at the Niigata City General Hospital and the other participating institutions in accordance with the Ethical Principles for Medical Research Involving Human Subjects (Declaration of Helsinki).

#### **2.3 Results**

The percentage of patients with no psychiatric diagnosis was 61.3%, while those with a type of somatoform disorder was 15.5%, a markedly high rate. 12.5% of patients were diagnosed with mood disorders, 8.5% with anxiety disorders, and 2.2% with alcohol use (**Figures 1** and **2**).

We compared the results of our PRIME-MD study in Japan with a PRIME-MD study conducted in the USA [5]. The prevalence of any mood disorders in Japan is lower than that in the USA. In particular, the rate of major depression is far

*Prevalence and Comorbidity of Anxiety and Depressive Disorders in Studies of PRIME-MD… DOI: http://dx.doi.org/10.5772/intechopen.97218*

**Figure 1.**

*Prevalence of Mental Disorders Detected by PRIME-MD in Primary Care Patients in Japan (n = 601).*

**Figure 2.**

lower in Japan. Minor depression, however, is almost as common in Japan as in the USA. Moreover, the rate of prevalence of any anxiety disorders in Japan is lower than in the USA, while figures for panic disorder are similar in both countries (refer to **Table 1**).

Of the 12.5% of patients diagnosed with mood disorders, 5.0% (n = 29) were major depressive disorder, and 6.7% (n = 40) were minor depressive disorder. 4.2% (n = 21) of patients were diagnosed with panic disorder, only 5 patients with general anxiety disorder (GAD), and 4.2% (n = 25) with anxiety disorders not otherwise specified.

As for diagnosis (n = 93) of somatoform disorders, 6.3% of patients (n = 38) were diagnosed with multisomatoform disorder, 5.7% (n = 34) with somatoform disorders not otherwise specified and 3.5% (n = 21) with identified somatoform disorders (refer to **Figure 3**).

The odds ratio for co-occurrence of major depressive disorder with generalized anxiety disorders, with anxiety disorders (NOS), and with panic disorders was 11.5 (95% CI: 2.17–18.45) and 8.00 (95% CI: 3.19–20.07), 6.33 (95% CI: 2.17–18.45), respectively (refer to **Table 2**).

**Table 3** shows the prevalence of mental disorder in women and men detected by the PRIME-MD study in Japan (n-601). With regards to major depression, a


#### **Table 1.**

*The comparison of PRIME-MD study in Japan and USA.*

#### **Figure 3.**

*Comorbidity of mood disorders, panic disorders, anxiety disorders and somatoform disorders detected by PRIME-MD in Japan (n = 601).*


#### **Table 2.**

*Comorbidity of mood Disorders and anxiety Disorders by detected the PRIME-MD study in Japan (n = 601).*


*Prevalence and Comorbidity of Anxiety and Depressive Disorders in Studies of PRIME-MD… DOI: http://dx.doi.org/10.5772/intechopen.97218*

#### **Table 3.**

*Prevalence of Mental Disorder in Women and Men Detected by the PRIME-MD Study in Japan (n = 601).*

significantly higher odds ratio was observed in women than in men (p = 0.0449). Alternatively, the odds ratio for alcohol use in men far exceeds that for women (p = 0.0058) (**Table 3**).
